Re: Homo erectus, city dweller and sailor

On Sep 13, 10:06 am, "J.LyonLayden" <JosephLay...@xxxxxxxxx> wrote:
On Sep 13, 10:11 am, Tom McDonald <kilt...@xxxxxxxxxxxxx> wrote:





veritas wrote:

<snip>

I have so far just gotten to Google, I've tried and failed on others,
I know it's a pain. And answering you will keep me from finishing, but
I'll do it another night.
Look at all your postings of articles, one from 1955, one from 1995,
all the rest are 2003 to present. That is what I meant by little
study on a big event.

I did say that the articles I listed were a very, very small
sample from *one* Google Scholar search. Additionally, the
articles I listed (from the first two or three screens of the GS
search), were strictly limited to the question of how the Toba
eruption may have affected humans. There were far more articles
that talked about the geology of the thing, as well as its
effects on other animals.

There is big study on this big event. But it is mostly in the
professional literature across a number of sciences, and requires
the willingness to do the diligent work of finding, reading and
comprehending that literature. It is not hidden; it is not
scarce; it is not open just to a limited number of the 'washed'.

But it is work in progress. It isn't neat and tidy--yet. For that
reason, it can be much more fun for laymen to read a
popularizer's writing on the issue, and the most available
popularizers don't do justice to the complexity or current
tentativeness of the actual state of scientific play.

I had read when I was young about the fellow in
India who while making a dig went through 13 feet of ash, and there
was talk, but there was very little information I could find up until
the late ninties. Now, I may have not have access to the right
sources, but I found very few studies, and they stated some facts, but
certainly not a complete story of what would have happened. Of
course, this all does take time.

Yes it does. And you would not expect a tidy, complete story on
an event like the Toba eruption, and its sequallia. (unless you
were a Han***, et al., devotee).

I understand the desire for getting the whole story. For, if you
will, 'fitting all the pieces of the puzzle together'. But
scientists don't write the end of the story (or, in another
analogy, don't draw the picture on the cover of the puzzle box)
until the evidence that tests the theories warrants it.

Toba is still too early in the process to write the ending, or
draw the puzzle box image.

As for the historians, I see just the opposite. They love to
complete the puzzle, but will leave out pieces that do not fit, or
cannot fit. A good example is almost any history book of the United
States. Wonderful, magical experiment, this country.

You aren't talking about scholarly historians here, for the most
part. You're talking about textbooks (which must be written in
such a way that elected school boards around the country will
accept them); and popular works which also have to find an audience.

Yet even there, we do have a number of very good popular works
that deconstruct familiar but erroneous stories of our history.

Do modern histories of the US tell us that Columbus was the first
known guy from the Old World to come here (well, not mainland
America)? No. Now, since the discovery of the Norse presence in
L'anse aux Meadows, the history books say the Norse (at least)
were here first.

History books change as our knowledge of our past--to a large
extent informed by archaeology (including that of the
underclasses older histories mostly ignored)--improves.

Then read "A
People's History of the United States" by Howard Zinn told from the
underbelly of American society. You say to yourself, "Oh, the others
failed to mention some of this." It's told from a different point of
view and the other histories could have mentioned some things, but it
really didn't fit the "image" of our country. So they do leave out
some pieces of the jigsaw puzzle if it doesn't fit, or they simply
can't find a place to put it. That is one of the things I look for in
reading any history. Do I have anything to compare it with? Did he
have any axes to grind, or just a plain straightforward telling it
like he knows history writer? If he had an axe to grind, that doesn't
make it untrue, you just think you should look some more.

You have to distinguish between historians who are trying to tell
a coherent, simplified history (as most elementary and secondary
textbooks must), and historians who are working away on the edges
of what we know for sure, trying to put together a more complete,
accurate and open-eyed story.

Again, much of this is not easily available in your local
Borders. More of it is probably available through, for instance,
Amazon. But still, probably the largest bunch of cutting-edge,
shake up the pieces of the incomplete puzzle, exist in the
professional historians' literature. As with the scientific
literature, it is there, but it requires the willingness to look
for it and the ability to comprehend it once you find it.

As I had said, this started long ago, in the late ninties were the
times for speculation that some stunning had happened. You have to
remember that when I was small, the answer in science class to the
extinction of the Dinosaurs was, "Nobody knows.". We have ideas now
but then no one speculated.

Oh, how wrong you are. There was quite a lot of speculation (even
hypotheses, and possibly theories). They included the lava flows
that created the Deccan Traps; the development and spread of
flowering plants and grasses; disease; plate tectonics changing
the geography and climate of the late Cretaceous; and probably
some I'm missing.

Until the Alvarez's work on Chixilub gave a believable mechanism
for the extinction (though perhaps not the entire extinction so
much as the coup de gras--the jury is still out on that), the
other hypotheses were being actively pursued. AFAIK, they still
are, although perhaps not with the same goal as before.

About humans it was not much different
until technology hit and we could do some real testing.

This should tell you something.

It has been a
hot item for 10-15 years, but little was curculated that I had come
across. It's just that it has been the rage for the past few years.
Especially with the human genome project.
Before, you heard the same story, they knew a small number of
Neanderthal were around, but what had become of the other species and
we became who we became, was that we evolved slowly from lesser
species into what we are today.

Not 'lesser species', but different species. Biological evolution
is not directional.

I'm not sure when the change came,
but it was gradual until DNA became the hot studies.

Darwin didn't have a biological mechanism for evolutionary
change. When Mendel's genetic studies got more play, and genetics
was added to Darwin's work to create the Neo-Darwinian Synthesis,
evolution was placed on a firmer, more scientific footing. When
the discover of DNA gave *genetics* a firmer footing, the
floodgates opened.

But the work takes time, and it is still early days for the
potential of DNA to tell us more about ourselves and our ancestors.

As for 75% of all animals, I would have to go back and try to find
the references I used at the time. (five years ago). I didn't realize
I would be using the references and I didn't keep a log. Damn me. I
would have to think that meant 75% of a species but I have no idea,
and I don't think anyone has studied what species went extinct and
what survived, or where. I do not believe that marine life was
mentioned at all. That is one of the things I meant by still articles
and soforth about it but no big studies.

People throw that %75 around loosely. You say %75 at the time of Toba.
Others say %75 at the end of the ice age.

The truth is that %70 of megafauna and a bunch of others died in the
pleistocene between 50,000 and 10,000 years ago. The highest occurence
of near simultaneous species extinctions during that period is the
last couple millenia of the last ice age, not at the time of Toba,
somewhere around 10,000-12,000. Granted, species died at the time of
Toba, especially in Australia, and the human and the bison bottleneck
may have occurred around that time, but the extinctions aren't as
concentrated as they were at the end of the last glacial maximum.







Keep looking. I'll wait.

As for the ice ages, if you look at the temperture levels from the
Greenland ice sample cores, you see that it dropped to it's lowest
level since about 140,000 years ago. It was really cold. If you read
any of the articles I'm sure you saw what they estimated to be a 1,000
year instant deep freeze. I know we have been in a million year "ice
age", (4 million?)but as you also know, it comes and goes apparently,
as I see anyway with the tilt to the sun. About 100,000 year cycles,
with little ones in between. I got my stats from "Prehisotoric
Europe". It shows the big drop about 140,000 years ago, and an almost
as big when Mt. Toba went off. The information was from the sample
cores. I'll do more later. Regards, Ken

AIUI, there have been at least four major ice ages (as I'm using
the term--millions of years of advances and retreats, followed by
long periods of moderated climate.

Actually there have been 21 or 22 during the last million years,
according to Diamond.





The big thing in all of what you write is that science and
history move. The leading edge is always uncertain and filled
with hypotheses that are not ready for prime time. If a layman is
looking for a nice, neat

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The estimate given by Michael Rampino, biologist and geologist at New
York University placed plants that died in the Northern Hemisphere
with the eruption of Mt. Toba at 75% of all plants. If that is so, no
plants to eat, no plant eaters, no carnivores with much food. But I
also see there is so much debate on exactly what happened, we are all
going to have to wait and let the people do their work and sort it
out. The one thing we are sure of is the 10,000 DNA combinations that
came out of Africa 55-50,000 years ago and took over the world.
Everything else seems to be up in the air. Regards, Ken

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